This invention relates to an improved supplemental support pad in general, and in particular to a multilayer pad having a central foam layer encased in fabric material and secured together by stitching.
Foam materials are widely used and well known for being incorporated into mattresses or mattress supplements for resilient support of persons. Numerous products are available in both commercial and medical markets to be placed on top of an existing mattress or other support surface as a supplement thereto. Typically such mattress cushions comprise a layer of foam material, such as several inches thick or more, with various cuts or incorporating other surface and subsurface features for improved performance. Such mattress cushions generally do not have their own fabric coverings and are not intended to be rolled up and transported to different locations. Several patents assigned to the present Assignee and illustrating examples of foam support pads are U.S. Pat. Nos. 4,603,445 (Spann, issued Aug. 5, 1986); 4,686,725 (Mitchell, issued Aug. 18, 1987); 4,700,447 (Spann, issued Oct. 20, 1987); and 4,862,538 (Spann et al., issued Sept. 5, 1989).
As manufacturers have attempted to incorporate the advantages of foam into different products, various coverings or the like have been applied to foam. For example, Kocher (U.S. Pat. Nos. 4,305,988 and 4,333,978) relate to a finished product comprising a plurality of foam cables in parallel and respectively surrounded by ultrasonically weldable materials which are ultrasonically spot welded to each other along substantially parallel, spaced apart weld seams. The foam cables or other strands of material are not ultrasonically weldable, and must be arranged in strips so that the weld seams may be created between adjacent strands or cables. In general, a finished product created with such methodology can be made into different sized products, such as a stadium cushion, chaise lounge cover, or exercise pad. It has been known to roll up commercial products of such construction and secure their rolled up condition with straps or the like. However, the technique completely prevents providing a product with an integral or continuous foam layer, or one which has natural fabric coverings or other materials which are not ultrasonically weldable. Also, irregular weld spots or failed weld spots obviously result in deficiencies in the finished product.
Natural fabric material can in general provide numerous desired features and advantages as a covering for a support surface for a person. For example, it is well known to place a towel, such as made of cotton terry cloth material or the like, across a chair or chaise lounge, or directly onto a ground surface such as sand at the beach or grass at a picnic. Absorbency and washability are two important advantages of such material for such uses. Breathability of the material is also an advantage, and terry cloth material with fitted corners have been adapted for use directly on chaise lounges.
Some manufacturers have attempted to combine the advantages of foam and fabric. For example, a beach matt product of Sure Fit products of Bethlehem, Pa., comprises a solid foam piece surrounded by a terry zippered case, which is removable to permit the terry cloth to be washed. The terry cloth is polyester rather than cotton or other natural fabric and so does not have breathability or absorbability advantages. Furthermore, the only securement of the outside cover to the solid foam pad is the zippered pillowcase type arrangement, which would not prevent bunching, gathering, or other problems. Also, no straps of any type are provided for either securing the pad to a chair or maintaining the pad in a rolled up condition. Without any form of stitching, the pad is not particularly adapted to be rolled up. In fact, attempts to roll up such a pad could exacerbate fit problems between the relatively loose cover and the foam piece.
Particularly in connection with very inexpensive exercise pads, diaper changing pads, or the like, it has been known to cover sections of foam with vinyl, with the resulting pad being foldable along the foam sections due to formation of vinyl "hinges" between such sections. Foam covered with vinyl is generally not capable of being rolled up and can only be folded at such "hinges." One attempt to solve this problem by the manufacturer of a molded exercise pad has been to create panels of descending size in a longitudinal direction of the pad. The pad cannot roll up, but can be folded up in triangles. It has also been known to combine a foam piece with vinyl on one side and terry cloth on another for use on such as chaise lounges. No stitching or quilting is provided in such structure so that foldability and fit problems still persist.
Another common problem with vinyl covered foam exercise pads is that folded vinyl strips have been secured as edging about the periphery of the foam layer. Such vinyl edging frequently is less durable than desired, particularly as relates to its continued securement to the pad. Vinyl edging which is repeatedly bent, such as adjacent to fold lines of a vinyl covered foam pad, frequently will work loose from the pad. Also, stitching generally does not hold well to the vinyl.
It has been generally known to stitch fabric to foam or some other resilient material, in connection with automobile upholstery or similar. Virtually any multi-needle quilting machine can perform such stitching, which is typically in straight lines or channels in automobile upholstery materials. Stitching of such materials may also be used in the ticking of a mattress, but most frequently quilting on such products is in the form of some ornamental pattern rather than a straight line. Obviously, neither conventional mattress products nor automobile upholstery products are suitable for portable use as a supplemental support pad for chaise lounges, stadium seats, or as exercise pads, diaper changing pads, or the like.